A novel SERS platform based on flower-like Bi₂WO₆-GO for the quantification of sepsis-associated biomarker procalcitonin

Procalcitonin (PCT) is a promising biomarker for identification of the origin and severity of sepsis, which is a deadly body infection. However, traditional diagnostic tools exhibited challenges in complicated instruments, sensitivity and time consuming. Herein, we created a highly sensitive and selective surface-enhanced Raman scattering (SERS) platform for PCT monitoring based on flower-like Bi₂WO₆-graphene (Bi₂WO₆-GO), which was created as a chemical mechanism (CM)-based SERS substrate with high stability as well as a remarkable enhancement factor (EF) value of 2.07 × 10⁸. The high EF value was primarily attributed to the efficient charge transfer (CT) between Bi₂WO₆-GO and 4-(2-(3-(dicyanomethylene)-5,5-dimethylcyclohex-1-en) vinyl) phenyl) boronic acid (BP) as a Raman reporter. The BP molecule was designed to play double key roles as a Raman reporter as well as a recognition probe. Owing to the specially designed BP molecule recognition of PCT and the high SERS effects of BP on Bi₂WO₆-GO, the developed SERS platform was employed for ultrasensitive and selective PCT quantification with a limit of detection down to 0.31 pg/mL in less than 8 min. The developed platform was also successfully utilized for early monitoring in sepsis rats, demonstrating practical potential for pathogene screening.